Template replication

ABSTRACT

Methods, systems, and apparatus for identifying dimensional attributes of a first active area of a template; based at least in part on the dimensional attributes of the first active area, determining a desired magnification correction of a second active area of a substrate; determining an out-of-plane distortion of the template, the substrate, or both; applying a back pressure to the template, the substrate, or both, to compensate for the out-of-plane distortion of the template, the substrate, or both; after compensating for the out-of-plane distortion of the template, the substrate, or both: i) contacting an imprint resist positioned on the substrate with the template such that pattern features in the first active area are filled by the imprint resist, and ii) applying an additional back pressure to the template, the substrate, or both, wherein the additional back pressure is selected such that the second active area exhibits the desired magnification correction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.15/350,714, which was filed on Nov. 14, 2016.

BACKGROUND

Nano-fabrication includes the fabrication of very small structures thathave features on the order of 100 nanometers or smaller. One applicationin which nano-fabrication has had a sizeable impact is in the processingof integrated circuits. The semiconductor processing industry continuesto strive for larger production yields while increasing the circuits perunit area formed on a substrate, therefore nano-fabrication becomesincreasingly important. Nano-fabrication provides greater processcontrol while allowing continued reduction of the minimum featuredimensions of the structures formed.

SUMMARY

Innovative aspects of the subject matter described in this specificationmay be embodied in methods that include the actions of identifying oneor more dimensional attributes of a first active area of a template;based at least in part on the identified dimensional attributes of thefirst active area of the template, determining a desired magnificationcorrection of a second active area of a substrate; determining anout-of-plane distortion of the template, the substrate, or both;applying a back pressure to the template, the substrate, or both, tocompensate for the out-of-plane distortion of the template, thesubstrate, or both; after compensating for the out-of-plane distortionof the template, the substrate, or both: i) contacting an imprint resistpositioned on the substrate with the template such that pattern featuresin the first active area of the template are filled by the imprintresist, and ii) applying an additional back pressure to the template,the substrate, or both, wherein the applied additional back pressure isselected such that the second active area of the substrate exhibits thedesired magnification correction.

Other embodiments of these aspects include corresponding systems andapparatus configured to perform the actions of the methods.

These and other embodiments may each optionally include one or more ofthe following features. For instance, the template is a master templateand the substrate is a replica template. The desired magnificationcorrection of the second active area of the substrate is determinedprior to contacting the imprint resist with the template. The additionalback pressure is applied to the template, the substrate, or both, whilethe template is in contact with the imprint resist positioned on thesubstrate. The out-of-plane distortion is one of a convex distortion ora concave distortion. Applying the additional back pressure to thetemplate, the substrate, or both includes applying a positive additionalback pressure to the template and a negative additional back pressure tothe substrate to increase a size of the second active area of thesubstrate based on the desired magnification correction. Applying theadditional back pressure to the template, the substrate, or both,includes applying a negative additional back pressure to the templateand a positive additional back pressure to the substrate to decrease asize of the second active area of the substrate based on the desiredmagnification correction. Curing the imprint resist to form a patternedlayer on the second active area of the substrate.

Innovative aspects of the subject matter described in this specificationmay be embodied in a system that includes a template chuck or holderconfigured to hold a template, the template including a first activearea associated with one or more dimensional attributes; a substratechuck or holder configured to hold a substrate, the substrate includinga second active area; a detection system configured detect a plane ofthe template, the substrate, or both; a pressure system configured toapply a back pressure to the template, the substrate, or both; acontroller in communication with the detection system and the pressuresystem, the controller configured to: i) determine, based on thedetected plane of the template, the substrate, or both, an out-of-planedistortion of the template, the substrate, or both, ii) determine, basedon the out-of-plane distortion of the template, the substrate, or both,a magnitude of back pressure to compensate for the out-of-planedistortion of the template, the substrate, or both, iii) provide a firstsignal to the pressure system such that the pressure system applies themagnitude of back pressure to the template, the substrate, or both, tocompensate for the out-of-plane distortion of the template, thesubstrate, or both, iv) after compensating for the out-of-planedistortion of the template, the substrate, or both, determine amagnitude of additional back pressure based on a desired magnificationcorrection of the second active area of the substrate, and v) provide asecond signal to the pressure system such that the pressure systemapplies the magnitude of additional back pressure to the template, thesubstrate, or both, such that the second active area of the substrateexhibits the desired magnification correction.

Other embodiments of these aspects include corresponding methodsperformed by the system.

These and other embodiments may each optionally include one or more ofthe following features. For instance, the template is a master templateand the substrate is a replica template. A fluid dispense systemconfigured to dispense an imprint resist on the substrate; and atranslation system configured to provide relative movement between thesubstrate and the template such that the template contacts the imprintresist positioned on the substrate to fill pattern features in the firstactive area of the template with the imprint resist. The pressure systemis configured to apply the additional back pressure to the template, thesubstrate, or both, while the template is in contact with the imprintresist. An energy source to provide energy to cure the imprint resistforming a patterned layer on the second active area of the substrate.The out-of-plane distortion is one of a convex distortion or a concavedistortion. The pressure system, based on the second signal, isconfigured to apply a positive additional back pressure to the templateand a negative additional back pressure to the substrate to increase asize of the second active area of the substrate. The pressure system,based on the second signal, is configured to apply a negative additionalback pressure to the template and a positive additional back pressure tothe substrate to decrease a size of the second active area of thesubstrate based on the desired magnification correction.

Particular implementations of the subject matter described in thisspecification can be implemented so as to realize one or more of thefollowing advantages. Implementations of the present disclosure provideminimizing, if not preventing, image placement error of the replicatemplate and magnification control of the replica template.

The details of one or more embodiments of the subject matter describedin this specification are set forth in the accompanying drawings and thedescription below. Other potential features, aspects, and advantages ofthe subject matter will become apparent from the description, thedrawings, and the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a simplified side view of a lithographic system inaccordance with embodiments of the present invention.

FIG. 2 illustrates a simplified side view of the substrate shown in FIG.1 having a patterned layer positioned thereon.

FIG. 3 illustrates a chucking system.

FIGS. 4A, 5A illustrate a template that is subjected to an out-of-planedistortion.

FIGS. 4B, 5B illustrate the template after compensation for theout-of-plane distortion.

FIGS. 6, 7 illustrate a template and a substrate subjected to amagnification correction.

FIG. 8 illustrates an example method of providing magnification controlof a substrate.

DETAILED DESCRIPTION

This document describes methods and systems that identify dimensionalattributes of a first active area of a template; based at least in parton the dimensional attributes of the first active area, determine adesired magnification correction of a second active area of a substrate;determine an out-of-plane distortion of the template, the substrate, orboth; apply a back pressure to the template, the substrate, or both, tocompensate for the out-of-plane distortion of the template, thesubstrate, or both; after compensating for the out-of-plane distortionof the template, the substrate, or both: i) contact an imprint resistpositioned on the substrate with the template such that pattern featuresin the first active area are filled by the imprint resist, and ii) applyan additional back pressure to the template, the substrate, or both,wherein the additional back pressure is selected such that the secondactive area exhibits the desired magnification correction.

FIG. 1 illustrates an imprint lithography system 100 that forms a reliefpattern on a substrate 102. The substrate 102 may be coupled to asubstrate chuck 104. In some examples, the substrate chuck 104 caninclude a vacuum chuck, a pin-type chuck, a groove-type chuck, anelectromagnetic chuck, and/or the like. Exemplary chucks are describedin U.S. Pat. No. 6,873,087, which is hereby incorporated by referenceherein. The substrate 102 and the substrate chuck 104 may be furthersupported by a stage 106. The stage 106 provides motion about the x-,y-, and z-axes. The stage 106, the substrate 102, and the substratechuck 104 may also be positioned on a base (not shown).

The imprint lithography system 100 further includes an imprintlithography template 108 that is spaced-apart from the substrate 102. Insome examples, the template 108 includes a mesa 110 (mold 110) thatextends from the template 108 towards the substrate 102. In someexamples, the mold 110 includes a patterning surface 112. The template108 and/or the mold 110 may be formed from such materials including, butnot limited to, fused-silica, quartz, silicon, organic polymers,siloxane polymers, borosilicate glass, fluorocarbon polymers, metal,hardened sapphire, and/or the like. In the illustrated example, thepatterning surface 122 includes a plurality of features defined byspaced-apart recesses 124 and/or protrusions 126. However, in someexamples, other configurations of features are possible. The patterningsurface 112 may define any original pattern that forms the basis of apattern to be formed on substrate 102.

The template 108 may be coupled to a template chuck 128. In someexamples, the template chuck 128 can include a vacuum chuck, a pin-typechuck, a groove-type chuck, an electromagnetic chuck, and/or the like.Exemplary chucks are described in U.S. Pat. No. 6,873,087, which ishereby incorporated by reference herein. Further, the template chuck 128may be coupled to an imprint head 130 such that the template chuck 128and/or the imprint head 130 may be configured to facilitate movement ofthe template 118.

The imprint lithography system 100 may further comprise a fluid dispensesystem 132. The fluid dispense system 132 may be used to deposit apolymerizable material 134 on the substrate 102. The polymerizablematerial 134 may be positioned upon the substrate 102 using techniquessuch as drop dispense, spin-coating, dip coating, chemical vapordeposition (CVD), physical vapor deposition (PVD), thin film deposition,thick film deposition, and/or the like. In some examples, thepolymerizable material 134 is positioned upon the substrate 102 beforeand/or after a desired volume is defined between the mold 110 and thesubstrate 102. The polymerizable material 134 may comprise a monomer asdescribed in U.S. Pat. No. 7,157,036 and U.S. Patent ApplicationPublication No. 2005/0187339, all of which are hereby incorporated byreference herein. In some examples, the polymerizable material 134 ispositioned upon the substrate 102 as a plurality of droplets 136.

Referring to FIGS. 1 and 2 , the imprint lithography system 100 mayfurther comprise an energy source 138 coupled to direct energy 140 alonga path 142. In some examples, the imprint head 130 and the stage 106 isconfigured to position the template 108 and the substrate 102 insuperimposition with the path 142. The imprint lithography system 110may be regulated by a processor 144 in communication with the stage 106,the imprint head 130, the fluid dispense system 132, and/or the energysource 138, and may operate on a computer readable program stored in amemory 146.

In some examples, the imprint head 130, the stage 106, or both, vary adistance between the mold 110 and the substrate 102 to define a desiredvolume therebetween that is filled by the polymerizable material 134.For example, the imprint head 130 may apply a force to the template 108such that the mold 110 contacts the polymerizable material 134. Afterthe desired volume is filled by the polymerizable material 134, theenergy source 138 produces energy 140, e.g., broadband ultravioletradiation, causing the polymerizable material 134 to solidify and/orcross-link conforming to shape of a surface 148 of the substrate 102 andthe patterning surface 122, defining a patterned layer 150 on thesubstrate 102. In some examples, the patterned layer 150 may comprise aresidual layer 152 and a plurality of features shown as protrusions 154and recessions 156, with the protrusions 154 having a thickness t₁ andthe residual layer 152 having a thickness t₂.

The above-described system and process may be further implemented inimprint lithography processes and systems referred to in U.S. Pat. No.6,932,934, U.S. Patent Application Publication No. 2004/0124566, U.S.Patent Application Publication No. 2004/0188381, and U.S. PatentApplication Publication No. 2004/0211754, each of which is herebyincorporated by reference herein.

As previously described, the template 108 and the mold 110 make directcontact with the polymerizable material 134 deposited on the substrate102 (e.g., a semiconductor wafer). Because such direct contact is made,it is generally recognized that the lifetime of the template 108 can belimited. As a result, known strategies have been adopted to account forthe limited template lifetime. For example, a master template isfabricated using standard techniques, such as electron beam (e-beam)writing, to form a desired pattern into the master template. This mastertemplate is not directly used, however, to form patterns, e.g., on thesubstrate. Instead, a replication process is typically employed tocreate multiple replica templates, which are then used to directly formpatterns on the substrate as previously described in FIGS. 1 and 2 . Thereplication process likewise involves the use of nanoimprintlithography, with the master template used to transfer its pattern intoa polymerizable material deposited on the surface of a replica templatesubstrate (or “blank”), followed by solidification, separation andadditional processing, e.g., etching, to transfer a corresponding reliefimage into the replica template substrate, thereby forming the replicatemplate. In this instance, the replica template carries an inversepattern of that of the master template. Such a replica itself can beused to create a further replica (i.e., a replica of a replica) in whichcase the further replica template would carry the same pattern as thatof the master template.

To that end, during patterning of a wafer (e.g., for semiconductordevices) utilizing the replica template, as described above with respectto FIGS. 1 and 2 , the process can be impacted by the ability of theimprint lithography system 100 to overlay the pattern being formed onthe wafer to the already existing pattern on the wafer. Very precisepattern placement is required for the device to function correctly.Therefore, it is important to be able to compensate for anymagnification errors present in the existing pattern on the wafer.

Provided herein are methods and systems to compensate for suchpreviously described magnification errors by controlling and adjustingthe magnification (i.e., size) of an active area of the replica templatesubstrate relative to the master template active area. These methodsrely, in part, on a template replication system and process that is ableto apply either positive or negative pressure to the master templateand/or the replica template substrate during imprinting.

FIG. 3 illustrates a chucking system 300. The chucking system 300 holds,or maintains a desired positioning, of one or more templates, e.g., thetemplate 108. The chucking system 300 includes a template chuck (orholder) 302, a substrate chuck (or holder) 304, a detection system 306,a first pressure system 308, a second pressure system 310, and acontroller 367. The template holder 302 and the substrate holder 304 areboth similar to the template chuck 128, mentioned above. Further, thetemplate holder 302 is coupled to a template 311 (i.e., holds, orchucks, the template 311), and the substrate holder 304 is coupled to asubstrate 312 (i.e., holds, or chucks, the substrate 312).

The template 311 includes a first active area 340. The first active area340 can include pattern features 341, similar to the recesses 124 andprotrusions 126 of FIG. 1 , and can include the region that activelyforms corresponding features in the substrate 312. The first active area340 can include dimensional attributes, such as dimensional attributesin the x and y directions. The substrate 312 includes a second activearea 342 that corresponds to the first active area 340, and can includethe region that has features formed therein by the first active area340.

In some examples, the template 311 is a master template and thesubstrate 312 is a replica template substrate (or blank). In someexamples, the template 311, the substrate 312, or both, include a hollow(cored-out) body. That is, a thickness of the template 311, thesubstrate 312, or both, proximate to the first active area 340 and thesecond active area 342, respectively, is substantially thinner than arespective thickness of the template 311, the substrate 312, or both,outside of the corresponding active areas. In some examples, thetemplate 311, the substrate 312, or both, includes a substantiallyuniform thickness across the body of the respective template 311, thesubstrate 312, or both.

Each of the template chuck 302 and the substrate chuck 304 can includechannels 320. The channels 320 of the template chuck 302 extend betweenthe first pressure system (or pressure source) 308 and one or morerespective chambers 322 a, 322 b, 322 c (collectively referred to aschambers 322); and the channels 320 of the substrate chuck 304 extendbetween the second pressure system (or pressure source) 310 and one ormore respective chambers 324 a, 324 b, 324 c (collectively referred toas chambers 324). The chambers 322 are defined between the templatechuck 302 and the template 311 and the chambers 324 are defined betweenthe substrate chuck 304 and the substrate 312. The chambers 322, 324 canprovide cavities that a pressure (positive and/or negative) can beapplied to by the respective pressure system. For example, the channels320 can provide a pressure to the chambers 322, 324 via the appropriatepressure system 310 or 312. In some examples, the magnitude and/or thedirectionality of the pressure can vary for any subset of the chambers322, 324 depending on the desired application. In some examples, thenumber of channels 320 and chambers 322, 324 can vary depending thedesired application.

In the illustrated example, the chambers 322 b, 322 c can providecavities that enable holding of the template 311 by applying theappropriate pressures (negative pressure, or vacuum) by the firstpressure system 308 through the associated channels 320. Similarly, thechambers 324 b, 324 c can provide cavities that enable holding of thesubstrate 312 by applying the appropriate pressures (negative pressure,or vacuum) by the second pressure system 310 through the associatedchannels 320.

Further, in the illustrated example, the chamber 322 a provides a cavitythat facilitates adjusting of a distortion (e.g., out-of-plane), amagnification, or both, of the template 311 by applying the appropriatepressures by the first pressure system 308 through the associatedchannels 320, described further below. Similarly, the chamber 324 aprovides a cavity that facilitates adjusting of a distortion (e.g.,out-of-plane), a magnification, or both, of the substrate 312 byapplying the appropriate pressures by the second pressure system 310through the associated channels 320, described further below.

The detection system 306 can include one or more scanning probes thathave nanometer resolution to measure a plane of the template 311, thesubstrate 312, or both. The scanning probes can include on-tool lasersystems and air gauges, or off-line interferometers with nanometer scaleresolution.

The controller 367 can include a computing processing device (e.g.,processor) and can be in communication with the detection system 306,the first pressure system 308, and the second pressure system 310. Ingeneral, the controller 367 receives data inputs, detailed below, andprovides appropriate signals to the first pressure system 308, thesecond pressure system 310, or both, such that the appropriate pressuresystem applies appropriate pressure to one or more of the chambers 322 aand 324 a.

FIGS. 4A, 5A illustrate a template 400 that is subjected to anout-of-plane distortion. The template 400 can be similar to the template311 or the substrate 312 of FIG. 3 . To that end, the detection system306 can determine the out-of-plane distortion of the template 400.Determining the out-of-plane distortion of the template 400 can includemeasuring a natural shape of the template 400 when the template 400 isnot subjected to pressure from a pressure source (e.g., the firstpressure system 310 or the second pressure system 312). In someexamples, the initial shape of the template 400 can include a concave ora convex shape. In some examples, when the template 400 is the substrate312, the detection system 306 can determine the out-of-plane distortionof the template 400 prior to forming a pattern in the template 400 or ina material positioned on the template 400, e.g., as described above withrespect to FIGS. 1 and 2 .

In the illustrated example of FIG. 4A, the detection system 306 candetermine that the out-of-plane distortion of the template 400 includesa convex distortion from the perspective of the associated templatechuck. In the illustrated example of FIG. 5A, the detection system 306can determine that the out-of-plane distortion of the template 500includes a concave distortion from the perspective of the associatedtemplate chuck.

FIG. 4B, 5B illustrates the template 400 after compensation for theout-of-plane distortion, shown in FIGS. 4A, 5A, respectively.Specifically, with respect to FIG. 4B, a back pressure, e.g., a vacuum(or negative) pressure, is applied to the template 400 to compensate forthe convex out-of-of plane distortion. Further, with respect to FIG. 5B,a back pressure, e.g., a positive pressure, is applied to the template400 to compensate for the concave out-of-of plane distortion.

The controller 367 can determine the magnitude of the back pressureapplied to the template 400 based on the detected plane of the template400, and specifically, the out-of-plane distortion of the template 400.In some examples, the controller 367 determines the magnitude of theback pressure based on the magnitude and the degree of the determinedout-of-plane distortion of the template 400. In some examples, thecontroller 367 determines the magnitude of the back pressure such that adesired plane (or shape profile) of the template 400 is obtained, e.g.,a substantially flat plane. The controller 367 then provides a signal tothe appropriate pressure system such that the appropriate pressuresystem applies the back pressure with the determined magnitude.

In some examples, when the template 400 is the template 311, the firstpressure system 308, in response to the signal from the controller 367,applies the back pressure to the template 311 via the channels 320 andthe chamber 322 a to compensate for the out-of-plane distortion of thetemplate 311. In the illustrated example of FIG. 4B, the first pressuresystem 308 applies a vacuum (or negative) pressure to the chamber 322 asuch that the portion of the template 311 proximate to the chamber 322 ais in a desired configuration or plane, and specifically, the firstactive area 340 of the template 311 is pulled towards the vacuumpressure source. That is, the first pressure system 308 applies a vacuumpressure to the chamber 322 a to obtain a desired shape profile of thefirst active area 340 of the template 311. Similarly, when the template400 is the substrate 312, the second pressure system 310 applies theback pressure to the substrate 312 via the channels 320 and the chamber324 a to compensate for the out-of-plane distortion of the substrate312, including obtaining a desired shape profile of the second activearea 342 of the substrate 312, analogous to that described with respectto the template 311.

In the illustrated example of FIG. 5B, the first pressure system 308, inresponse to the signal from the controller 367, applies a positivepressure to the chamber 322 a such that the portion of the template 311proximate to the chamber 322 a is in a desired configuration or plane,and specifically, the first active area 340 of the template 311proximate to the chamber 322 a is pushed away from the positive pressuresource. That is, the first pressure system 308 applies a positivepressure to the chamber 322 a to obtain a desired shape profile of thefirst active area 340 of the template 311. Similarly, when the template400 is the substrate 312, the second pressure system 310 applies theback pressure to the substrate 312 via the channels 320 and the chamber324 a to compensate for the out-of-plane distortion of the substrate312, including obtaining a desired shape profile of the second activearea 342 of the substrate 312, analogous to that described with respectto the template 311.

In some examples, the first pressure system 308 applies the backpressure to the template 311 via the channels 320 and the chamber 322 ato compensate for the out-of-plane distortion of the template 311concurrently with the second pressure system 310 applying the backpressure to the substrate 312 via the channels 320 and the chamber 324 bto compensate for the out-of-plane distortion of the substrate 312.

To that end, the out-of-plane distortion (i.e., initial shape) of thetemplate 311 and the substrate 312 are compensated for, thereby settlingthe contact plane of both the template 311 and the substrate 312. As aresult, determination of the magnification error/correction of thesubstrate 312, and compensation thereof, described below, isfacilitated. Specifically, if the out-of-plane distortion of thetemplate 311 and the substrate 312 is not compensated prior todetermination of the magnification error/correction of the substrate312, the substrate 312 can include unpredictable magnification errorand/or image placement error relative to the template 312. In otherwords, in some examples, the out-of-plane distortion of the template 311and/or the substrate 312 is determined and corrected for prior todetermination and correction of the magnification correction of thesubstrate 312, described below.

The magnification correction of the substrate 312 can be based on atleast the dimensional attributes of the first active area 340 of thetemplate 311. In some examples, after patterning of a wafer (substrate)with the substrate 312 serving as a patterning template, the patternedwafer, and in particular an active area of the patterned wafer, can beassociated with dimensional attributes (e.g., along the x and ydirections). To that end, based on a comparison of these dimensionalattributes of the patterned wafer, and the dimensional attributes of thefirst active area 340 of the template 311, the magnification correctionof the second active area 342 of the substrate 312 can be determined.For example, the dimensional attributes of the patterned wafer can belarger or smaller in relation to the first active area 340 of thetemplate 311.

In some examples, the magnification correction of the second active area342 of the substrate 312 is determined and provided as an input signalto the controller 367. The controller 367, based on the magnificationcorrection of the second active area 342 of the substrate 312, candetermine the magnitude of an additional back pressures, describedbelow, such that the second active area 342 of the substrate 312exhibits the desired magnification correction.

FIGS. 6 and 7 illustrates a template 602 and a substrate 604 subjectedto a magnification error. The template 602 can be similar to thetemplate 311 of FIG. 3 or the template 400 of FIGS. 4 b, 5 b , andinclude a first active area 640 similar to the first active area 340.The substrate 604 can be similar to the substrate 312 of FIG. 3 , or thetemplate 400 of FIGS. 4 b, 5 b , and include a second active area 642similar to the second active area 342. In some examples, the template602 can be the master template and the substrate 604 is the replicatemplate substrate (or blank). To that end, after compensating for theout-of-plane distortion of the template 602 and/or the substrate 604, asdescribed above with respect to template 400 of FIGS. 4 a, 4 b, 5 a, and5 b , respectively, magnification correction or adjustment can beapplied to the substrate 604.

In some implementations, after compensating for the out-of-planedistortion of the template 602 and/or the substrate 604, an imprintresist 610 is positioned on the substrate 604 and is contacted with thetemplate 602 such that pattern features in the first active area 640 ofthe template 602 are filled by the imprint resist 610. For example, theimprint resist 610 (e.g., the polymerizable material 134) can bepositioned on the substrate 604 by a fluid dispense system (e.g., thefluid dispense system 132). Furthermore, an imprint head (e.g., theimprint head 130) provides translation of the template 602 relative tosubstrate 604 such that pattern features (e.g., recessions 124) of thetemplate 602 are filled by the imprint resist 610. Moreover, the imprinthead provides translation of the template 602 relative to the substrate604 after compensating for the out-of-plane distortion of each of thetemplate 602 and the substrate 604.

In some embodiments, a first additional back pressure is applied to thetemplate 602 and/or a second additional back pressure is applied to thesubstrate 604 to compensate for the magnification error such that thesecond active area 642 of the substrate 604 exhibits the desiredmagnification correction. For example, the controller 367 determines amagnitude of the first additional back pressure and/or a magnitude ofthe second additional back pressure based on a desired magnificationcorrection of the second active area 642 of the substrate 604. Thecontroller 367 generates a signal based on such and provides the signalto the first pressure system 308 and/or the second pressure system 310.The first pressure system 308, based on the signal, applies the firstadditional back pressure to the template 602 via the appropriatechannels 320 and the chamber 322 a, and the second pressure system 310applies the second additional back pressure to the substrate 604 via theappropriate channels 320 and the chamber 324 b to compensate for themagnification error of the substrate 604. In some examples, the firstadditional back pressure opposes the second additional back pressure.That is, a direction of the first additional back pressure opposes adirection of the second additional back pressure. For example, the firstadditional back pressure can include a vacuum (negative) pressure, andthe second additional back pressure can include a positive pressure.Further, for example, the first additional back pressure can include apositive pressure, and the second additional back pressure can include avacuum (negative) pressure.

In the illustrated example of FIG. 6 , the first pressure system 308,based on the signal provided by the controller 367, applies a vacuum(negative) pressure to the chamber 322 a such that the portion of thetemplate 602 proximate to the chamber 322 a (e.g., the first active area640) is pulled away from the substrate 604, and the second pressuresystem 310, based on the signal provided by the controller 367, appliesa positive pressure to the chamber 324 a such that the portion of thesubstrate 604 proximate to the chamber 324 a (e.g., the second activearea 642) is pushed towards to the template 602. In this example, aconcave bend is induced in the first active area 640 of the template602, and a complementary convex bend is induced in the correspondingsecond active area 642 of the substrate 604.

To that end, by applying a vacuum (negative) pressure to the chamber 322a and a positive pressure to the chamber 324 b to compensate for themagnification error, a size of the second active area 642 of thesubstrate 604 is decreased. That is, the second active area 642 of thesubstrate 604 (e.g., along the x-y axis, or a curvature of a surface ofthe substrate 604) is increased (e.g., stretched), and the first activearea 640 of the template 602 (e.g., along the x-y axis, or a curvatureof a surface of the template 602) is decreased (e.g., shrunk). Theincrease in the second active area 642 of the substrate 604 and thedecrease in the first active area 640 of the template 604 is a result ofthe bowing (bending) of the active areas 640, 642 resulting from thevacuum pressure of the chamber 322 a and the positive pressure of thechamber 324 a.

Upon separation of the template 602 and the substrate 604, the bendingof the template 602 and the substrate 604 is removed (cessation of thepressure applied by the pressure sources 308 and 310). The substrate 602relaxes to its normal, unpressured state, and the second active area642, including a pattern formed therein, becomes slightly smallerrelative to its previous “stretched” state and to the first active area640 of the template 602, representing a decreased magnification.

In the illustrated example of FIG. 7 , the first pressure system 308,based on the signal provided by the controller 367, applies a positivepressure to the chamber 322 a such that the portion of the template 602proximate to the chamber 322 a (e.g., the first active area 640) ispushed towards the substrate 604 and the second pressure system 310,based on the signal provided by the controller 367, applies a vacuum(negative) pressure to the chamber 324 a such that the portion of thesubstrate 604 proximate to the chamber 324 a (e.g., the second activearea 642) is pulled away from the template 602. In this example, aconvex bend is induced in the first active area 640 of the template 602,and a complementary concave bend is induced in the corresponding secondactive area 642 of the substrate 604.

To that end, by applying a positive pressure to the chamber 322 a and avacuum pressure to the chamber 324 a to compensate for the magnificationerror, a size of the second active area 642 of the substrate 604 isincreased. That is, the second active area 642 of the substrate 604(e.g., along the x-y axis, or a curvature of a surface of the substrate604) is decreased (e.g., shrunk, contracted), and the first active area640 of the template 602 (e.g., along the x-y axis, or a curvature of asurface of the template 602) is increased (e.g., stretched). Thedecrease in the second active area 642 of the substrate 604 and theincrease in the first active area 640 of the template 602 is a result ofthe bowing (bending) of the active areas 640, 642 resulting from thepositive pressure of the chamber 322 a and the negative pressure of thechamber 324 a.

Upon separation of the template 602 and the substrate 604, the bendingof the template 602 and the substrate 604 is removed (cessation of thepressure applied by the pressure sources 308 and 310). The substrate 602relaxes to it's normal, unpressured state, and the second active area642, including a pattern formed therein, becomes slightly largerrelative to its previous “contracted” state and to the first active area640 of the template 602, representing an increased magnification.

In some examples, the pressure of the chamber 322 a and the pressure ofthe chamber 324 a are proportional. For example, in the illustratedexample of FIG. 6 , the magnitude of the vacuum pressure of the chamber322 a and the magnitude of the positive pressure of the chamber 324 aare substantially the same; and in the illustrated example of FIG. 7 ,the magnitude of the positive pressure of the chamber 322 a and themagnitude of the vacuum pressure of the chamber 324 a are substantiallythe same.

In some examples, the first pressure system 308 applies the firstadditional back pressure to the template 602 and/or the second pressuresystem 310 applies the second additional back pressure to the substrate604 while the imprint resist 610 is in contact with the template 602.Applying the first additional back pressure and/or the second additionalback pressure while the imprint resist 610 is in contact with thetemplate 602 can provide improved accuracy in the magnitude of the firstadditional back pressure and the second additional back pressure appliedto facilitate compensating for the out-of-plane distortion andmagnification error.

In a use-case example, both the master template (e.g., the template 311)and replica blank (e.g., the substrate 312) start as conventional 6 inchby 6 inch by 0.25-inch blank fused silica plates. The center 64 mm areasare then cored out and set to a thickness of 1.1 mm. The maximumpatterned area (i.e., active area) is 26 mm×33 mm, in the y and xdirections respectively, which is a semiconductor industry standard. Therelief patterns on the master template are transferred on to the 26mm×33 mm mesa centered in the cored out region of the replica template.

For example, under these conditions, if a positive pressure of 1 kPa isapplied to the master template, the resultant magnification change tothe replica template active area (e.g., the second active area 342), ascalculated using finite element analysis, will be −3.34 ppm in x and−3.48 ppm in y. Likewise, if a negative pressure of 1 kPa is applied tothe master template, the resultant magnification change to the replicatemplate active area (e.g., the second active area 342), again ascalculated using finite element analysis, will be 3.34 ppm in x and 3.48ppm in y. It will be understood that any combination of pressure addingto +/−1 kPa will result in the same magnification change for thereplica. If more or less magnification is required, the total back sidepressure can be changed accordingly. It will also be understood that arange of pressures can be applied provided that at no time can pressuresbe increased to the point where they begin to impact the vacuum forcesbeing used to hold the template and replica in place by their respectiveholding chucks.

Further, the thicknesses of the template and replica active areas can beas little as 0.100 mm and as large as 6.35 mm. In addition, the masterand replica thicknesses and cored out diameters can be the same ordifferent. In addition to fused silica templates and replicas, othertemplate materials are contemplated. Thermal nanoimprint lithography, asan example, uses a thermal process to cure the nanoimprint resist. Atypical template material used in thermal nanoimprint lithography issilicon. Additional possible template materials include polymers andplastics. For the cases of polymers and plastics, because the Young'smodulus are much lower than that of either silicon or fused silica,their thicknesses can be much greater than 1.1 mm, for exampleapproaching 5 to 6 mm or greater, and still achieve enough inducedbending from the applied back pressure to achieve the desired activearea alignment area adjustments. Furthermore, master templates andreplicas are also not confined to the 6 in x 6 in plate configuration.Silicon substrates, as an example, are often round, and have diametersranging from 50 mm up to 450 mm. Templates can also be plate shaped,with varying x and y dimensions as well as varying thicknesses.

FIG. 8 illustrates an example method of providing magnification controlof a substrate. The process 800 is illustrated as a collection ofreferenced acts arranged in a logical flow graph. The order in which theacts are described is not intended to be construed as a limitation, andany number of the described acts can be combined in other orders and/orin parallel to implement the process.

Dimensional attributes of a first active area of a template areidentified (802). For example, the first active area 340 of the template311 is associated with dimensional attributes along x and y directions.A desired magnification correction of a second active area of asubstrate is determined based at least in part on the dimensionalattributes of the first active area of the template (804). For example,the detection system 306 determines the desired magnification correctionof the second active area 342 of the substrate 312 based on thedimensional attributes of the first active area 340 of the template 311.An out-of-plane distortion of the template and/or the substrate isdetermined (806). For example, the detection system 306 determines theout-of-plane distortion of the template 311 and/or the substrate 312. Aback pressure is applied to the template and/or the substrate tocompensate for the out-of-plane distortion of the template and/or thesubstrate (808). For example, the first pressure system 308 applies theback pressure to the template 311 via the channels 320 and the chamber322 a to compensate for the out-of-plane distortion of the template 311and/or the second pressure system 310 applies the back pressure to thesubstrate 312 via the channels 320 and the chamber 324 a to compensatefor the out-of-plane distortion of the substrate 312.

After compensating for the out-of-plane distortion of the templateand/or the substrate, an imprint resist positioned on the substrate iscontacted with the template such that pattern features in the firstactive area of the template are filled by the imprint resist (810). Forexample, the template 602 contacts the imprint resist 610 positioned onthe substrate 604. Additionally, after compensating for the out-of-planedistortion of the template and/or the substrate, an additional backpressure is applied to the template and/or the substrate, the additionalback pressure is selected such that the second active area of thesubstrate exhibits the desired magnification correction (812). Forexample, the first pressure system 308 applies the first additional backpressure to the template 602 via the appropriate channels 320 and thechamber 322 a and/or the second pressure system 310 applies the secondadditional back pressure to substrate 604 via the appropriate channels320 and the chamber 324 a to compensate for the magnification error.

What is claimed is:
 1. An imprint lithography system comprising: atemplate chuck or holder configured to hold a template, the templateincluding a first active area associated with one or more dimensionalattributes; a substrate chuck or holder configured to hold a substrate,the substrate including a second active area; a detection systemconfigured detect a plane of the template, the substrate, or both; apressure system configured to apply a back pressure to the template, thesubstrate, or both; a controller in communication with the detectionsystem and the pressure system, the controller configured to: i)determine, based on the detected plane of the template, the substrate,or both, an out-of-plane distortion of the template, the substrate, orboth, ii) determine, based on the out-of-plane distortion of thetemplate, the substrate, or both, a magnitude of back pressure tocompensate for the out-of-plane distortion of the template, thesubstrate, or both, iii) provide a first signal to the pressure systemsuch that the pressure system applies the magnitude of back pressure tothe template, the substrate, or both, to compensate for the out-of-planedistortion of the template, the substrate, or both, iv) aftercompensating for the out-of-plane distortion of the template, thesubstrate, or both, determine a magnitude of additional back pressurebased on a desired magnification correction of the second active area ofthe substrate, and v) provide a second signal to the pressure systemsuch that the pressure system applies the magnitude of additional backpressure to the template, the substrate, or both, such that the secondactive area of the substrate exhibits the desired magnificationcorrection.
 2. The imprint lithography system of claim 1, wherein thetemplate is a master template and the substrate is a replica template.3. The imprint lithography system of claim 1, further comprising: afluid dispense system configured to dispense an imprint resist on thesubstrate; and a translation system configured to provide relativemovement between the substrate and the template such that the templatecontacts the imprint resist positioned on the substrate to fill patternfeatures in the first active area of the template with the imprintresist.
 4. The imprint lithography system of claim 3, wherein thepressure system is configured to apply the additional back pressure tothe template, the substrate, or both, while the template is in contactwith the imprint resist.
 5. The imprint lithography system of claim 3,further comprising an energy source to provide energy to cure theimprint resist forming a patterned layer on the second active area ofthe substrate.
 6. The imprint lithography system of claim 1, wherein theout-of-plane distortion is one of a convex distortion or a concavedistortion.
 7. The imprint lithography system of claim 1, wherein thepressure system, based on the second signal, is configured to apply apositive additional back pressure to the template and a negativeadditional back pressure to the substrate to increase a size of thesecond active area of the substrate.
 8. The imprint lithography systemof claim 1, wherein the pressure system, based on the second signal, isconfigured to apply a negative additional back pressure to the templateand a positive additional back pressure to the substrate to decrease asize of the second active area of the substrate based on the desiredmagnification correction.
 9. A method of manufacturing an article, themethod comprising: identifying one or more dimensional attributes of afirst active area of a template; based at least in part on theidentified dimensional attributes of the first active area of thetemplate, determining a desired magnification correction of a secondactive area of a substrate; determining an out-of-plane distortion ofeach of the template, the substrate, or both; applying a back pressureto the template, the substrate, or both, to compensate for theout-of-plane distortion of the template, the substrate, or both; aftercompensating for the out-of-plane distortion of the template, thesubstrate, or both, i) disposing an imprint resist on the substrate, ii)contacting the imprint resist with the template such that patternfeatures in the first active area of the template are filled by theimprint resist, and iii) applying an additional back pressure to thetemplate, the substrate, or both, wherein the applied additional backpressure is selected such that the second active area of the substrateexhibits the desired magnification correction; polymerizing the imprintresist to yield a polymeric layer; separating the template from thepolymeric layer; and transferring a pattern of the polymeric layer intothe substrate to yield the article.
 10. The method of claim 9, whereinthe article is a replica template.
 11. The method of claim 10, furthercomprising: disposing additional imprint resist on an additionalsubstrate; contacting the additional imprint resist with the replicatemplate; polymerizing the additional imprint resist to yield anadditional polymeric layer; and separating the additional substrate fromthe replica template to yield a patterned substrate.